Lime hydrating plant and process of lime hydrating as well as flue gas desulfurization plant with such a lime hydrating plant and process of flue gas desulfurization

Abstract

A lime hydrating plant is provided with an external cooler 16 in which the rawer solids portion which is recirculated into a return flow fluidizer 2 (hydrater) is cooled outside the hydrater. This means that less water has to be atomized into the return flow fluidizer 2 than by known plants in order to keep the adequate temperature essential for the hydrating process. Thus dew point decrease may be avoided and a highly reactive hydrated lime may be produced.

I claim: 
     
       1. A lime hydrating plant, comprising: a hydrator   means for injecting air and water into said hydrator to form a hydrated lime product,   means for precipitating solids from said product,   means for collecting said solids from said precipitating means, and   means for cooling said solids within said collecting means, wherein a line is positioned between said collecting means and said hydrator for returning cooled solids to said hydrator.   
     
     
       2. A hydrating plant according to claim 1, wherein said collecting means is a fluidization unit. 
     
     
       3. A hydrating plant according to claim 1,, wherein said precipitating means includes a raw precipitator and a fine precipitator. 
     
     
       4. A hydrating plant according to claim 1, wherein the collecting means includes an outlet for sending exhaust air to a fine precipitator. 
     
     
       5. A hydrating plant according to claim 3, wherein a hot air line is connected to said fine precipitator. 
     
     
       6. A hydrating plant according to claim 1, including means for controlling temperature of the water injected into said hydrator. 
     
     
       7. A hydrating plant according to claim 2, said hydrator includes a prededuster. 
     
     
       8. A combination lime hydrating and desulfurization plant, comprising: a hydrator   means for injecting air and water into said hydrator to form a hydrated lime product,   means for precipitating solids from said product,   means for collecting said solids from said precipitating means, and   means for cooling said solids within said collecting means, wherein a line is positioned between said collecting means and said hydrator for returning cooled solids to said hydrator,   an absorber for desulfurizing flue gas generated as a by-product of the hydrated lime product.   
     
     
       9. The plant of claim 8, including a second hydrator connected in parallel to said hydrator, and wherein said second hydrator is connected to a hydrated lime storage vessel. 
     
     
       10. The plant of claim 8, including an exhaust air conduit connecting the collecting means and the absorber.